Britain's United Nations ambassador says he hopes the U.N. Security Council will agree as soon as possible on a resolution imposing tough new sanctions on North Korea in response to its recent nuclear test and long-range rocket launch.

Matthew Rycroft told reporters Thursday that Britain is pressing for sanctions "that will go beyond traditional nonproliferation areas in order to demonstrate the seriousness of the test and the launch."

The United States and China are negotiating the text of a new resolution and the council pledged after Sunday's launch to "expeditiously" adopt a new resolution with "significant" new sanctions.

The U.S. and its allies want sanctions that go beyond the North's nuclear and missile programs but China, Pyongyang's ally, is reluctant to impose measures that could cause the country's economy to collapse.